Potential divider



Dec. 28, 1948. J. A. STAGNARO 2,457,787

POTENTIAL DIVIDER 3 Filed June 2, 1944 4o :lll l lk- 2s 21 2a 29 k .A..A .Lm..J.

Y'V' rIII" I"! Y" II" III I." "II IVY "I" INVENTOR JOHN A. STAGNARO ATTRNEY Patented Dec. 28, 1948 UNI TED .S OF Fl C E.

, .2,457,7sr. TO'I EN'HAL urvmER John A. .Stagnano, Fort Wayne, ImL,:assig-nor,xby mesne assignments, to Farns-worthW-Research Corporation,a corporation of Indiana Applicationlune 2; 1944, Serial No.*538 ,499

5 Claims. (Cl.-,250-17.5

'This invention relates to electron multipliers and is particularlydirectedito multistage multi pliers wherein, there is provided asfa'nintegral part thereof a potential dividenfor providing, .eratingpotentials.

It .is known-in the art that electron-multiplier tubes generallycomprise an electron-emitting cathode and a collector anode. Arranged.serially between the cathode andanode is a plurality of electrodeshaving high secondary electron-eminision properties. For acceleratingthe electron emission from each electrode a succ'ess'ively increasingpositive potential must be applied'thereto. It has been customary toderive the respecfi potentials from a voltage source'bymeans ofresistors. It'ischaract'eristic of present-day elec. tron multipliersthat no two are exactly alike with respect to inter-stageoperatingpotentials; Consequently, it is necessary *thateach individualtube beprovi'ded with its individual potential di- 'vider 'consistingofaplura-lity of resistors, each resistor being designed to providethe'properopera-ting potential between a certain pair of multiplierstages. Heretofore it has been the practice to dispose the resistors atrandom within a .tubechaesis withmespeeti-nedeads therefrom beingconnected to the electrodes pf the tube. Periodically, because of tube.failure and the like, replacement of the electron multiplier isnecessary. each multiplier are different, it isfnecessary',upo'n thereplacement of a tube towchange one or more of'theresistors to coincide"with the characteristics of the new tube. This entails removal -of oldresistors and redfesignof circuits andcauses undue. loss of operatingtime invaluable :app'aratus.

Hence, it is the principal objector thisinvention to provide as anintegral'part of an elect-ron multiplier a potential divider consistingof a plurality of resistors, each of which'is matched to the multiplier.1 "In accordance with: the present invention there is provided amultistage multiplier including an envelope having arranged therein aplurality of multiplier components, each component having individualcharacteristics. Connected to the multiplier components is a potentialdivider having components matched with respect to the characteristics ofthe multiplier components. There are also provided means for connectingthe potential divider with the multiplier and means for securing thedivider to the envelope t of the multiplier.

For a better understanding of the invention,

Since the electrical characteristicswof flit) din together with otherandtiurther objects thereof, reference-.zis made to. the followingdescription, taken ine connection with the accompanying drawing. :andits *scope will .be pointed. out-in the appended claims.

.In- :the L accompanying drawing;

Fig. 1 .is 'a sectionalrview of the device in operative relation *witha: .dissector' tube having mounted therein a multistage multiplier;

:Eig.x2-is= alsectional view of the device taken linear-21 cm Fig.1;..and.

:E'igJB i is a schematic wiring diagram showing accirenitincludingavpotential divider connected to the'vari-ous stagesntthemultiplier.

Reierringmarticularl-y to Figs. 1 and 2 of the 'drawingithererisrshown adissector tube I having .anaevacuatedxenvelope .2. Mounted at one end oirthe tube there is a "photosensitive electroncathn'de 73..Disposedadjacent the op posite end thereof in the rneck vportion' l ofthe envelopeithere is-mounted a multiplier :5 having aiiplura lityofserially arranged box-like electrodes suchtaszzt, 1i, :8: and 9.Adjacent the electrode?) islthe collecting anode I50.

fMounted'onrth-e neck portiont of the tube is arnnitaryelectrical.potentialudivider II. This homprisesia cylindricalcontainerI2 having a lowerend wall I'll, in'whic'h is centrally disposed anaperture I4. Secured to't'he wall l3"by screws or other suitablefastening means and extending "outwardly therefrom, in direct alignmentwith "theaperture M, is flanged tube 20. Disposedflwithin the inner Wallof the tube is a resilient member! 6 whichiis adapted tofrictionallyengage the neck portion 4 of the tube tosecurelyfholtl"the'device in operative position.

'S'ecured 1 ]oy=screws 'l5 and 3 l1 within the container f z andagainstthe wall-f3 thereof, there is arranged a pairfof annularinsulator members l a an-d I Si Mdunted-on the member I 9, by screws 22,23 and-"2331s -an-'=annuiar insulator plate 25 on -wvhich isflm'ounted aplurality of resistor-elemerits such as -7233.21, 28" and29hayingelectrical characteristics which match those of the multiplier wherebyto provide the desired electron acceleration and secondary emission.Each of the resistors is mounted on a pair of studs 30 and 3| which aresecured to the plate 25. Secured t0 the inner wall of the container Hthere is arranged a plurality of lugs such as 32 and 33, which areadapted to securely fasten the cover 34 at the open end of the device.Disposed in the inner side of the cover, there is provided an insulatorplate 35.

On the wall of the container ll there is pro- 3 vided a pair of openings36 and 31 through which may be passed the output conductors leading fromthe tube to whatever auxiliary apparatus may be required.

Referring to Fig. 3 of the drawing, there is shown the electricalconnections of the device in operative relation with the various stagesof the multiplier. The resistor element comprises series connectedresistors 26, 21, 28 and 29, across the end terminals of which isconnected a relatively high source of potential, such as a battery 40.Between each resistor is a tap, each tap being connected to therespective stages of the multiplier. From this arrangement there isimpressed upon each succeeding stage of the multiplier an increasinglyhigher positive voltage.

In accordance with the object of this invention,

there is provided a potential divider which is designed, constructed andpassed on to the user as an integral and permanently attached part ofeach individual multiplier tube. Each of the resistors in the dividerare chosen because of the particular individual requirements of thesuccessive multiplier stages. As stated hereinbefore, it is impossibleto manufacture multiplier tubes wherein the characteristics of themultiplier stages are identical in all respects. Thus it will be obviousto those skilled in the art that each tube requires anindividually-designed potential divider. Prior to this invention,replacement of an electron-multiplier tube in a given circuit requiredredesign of the potential source, but since applicant provides as apermanently attached part of the tube a potential divider matched to theelectrical characteristics of that tube, replacement of the tube willonly require removal of a defective tube and insertion of a new tube inthe tube socket. No alteration of the permanent circuit which forms apart of the tube chassis will be necessary.

While'there has been described what is at present considered thepreferred embodiment of the invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention, and it is, therefore,aimed in the appended claims to cover all such changes and modificationsas fall within the true spirit and scope of the invention.

What is claimed is:

1. An electron tube assembly comprising an envelope containing thereinan electron multiplier, and a potential divider permanently mounted onsaid envelope adjacent said multiplier and having electricalcharacteristics matched to those of said multiplier, said dividercomprising a plurality of series-connected resistors, each of which ismatched with and connected to one or more stages of said multiplier.

2. An electron tube assembly comprising an envelope containing thereinan electron multiplier, and a potential divider permanently mounted onsaid envelope adjacent said multi- 4 plier and having electricalcharacteristics matched to those of said multiplier, said dividercomprising a plurality of series-connected resistors, each of which ismatched with and connected to one or more stages of said multiplier, asupporting means for said divider comprising a cylindrical body portion,a neck portion fixed thereto and to said envelope and an insulating discWithin said cylindrical portion supporting said resistors.

3. An electron tube assembly comprising an envelope containing thereinan electron multiplier, and a potential divider permanently mounted onthe outside of said envelope and having fixed electrical characteristicsmatched to those of said multiplier, said divider comprising a pluralityof series-connected resistors, each of which is matched with andconnected to one or more stages of said multiplier, aresistor-supporting means comprising a container, an extension fixedthereto and to said envelope and an insulating member fixed within saidcontainer supporting said resistors.

4. An electron tube including a neck portion having mounted therein amultistage multiplier, a cylindrical container having at one end thereofa wall with a centrally-disposed aperture, a flanged cylindrical supportsecured to said wall and extending outwardly therefrom, a resilientmember mounted adjacent the inner wall of said support frictionallyengaging the neck of the tube, an insulating plate secured to said walland having a centrally-disposed aperture and a plurality of resistorsarranged symmetrically on said plate and connected to said multiplier.

5. An electron tube including a neck portion having'mounted therein amultistage multiplier, a cylindrical container, a support secured tosaid container adapted to engage the neck of the tube and an insulatorplate secured to said container having a plurality of resistorsconnected to said multiplier.

JOHN A. STAGNARO.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,699,011 Murphy Jan. 15, 19291,923,552 Murphy Aug. 22. 1933 1,981,115 Murphy Nov. 20, 1934 2,051,693Finch Aug. 18, 1936 2,078,304 Zworykin et a1 Apr. 27, 1937 r 2,252,752Bliss Aug. 19, 1941 2,257,942 Farnsworth Oct. 7, 1941 2,264,630Farnsworth Dec. 2, 1941 2,315,288 Knoop Mar. 30, 1943 FOREIGN PATENTSNumber Country Date 478,262 Great Britain Apr. 13, 1937

